All Articles - SQL Authority with Pinal Dave

SQL SERVER – Huge Transaction Log (LDF) for Database in Availability Group

February 12, 2016

SQL Error Messages, SQL Log, SQL Scripts, SQL Server, Transaction Log

One of my blog readers posted on Facebook asked following question about Huge Transaction Log:

Hi Pinal,
We are using AlwaysOn availability group for our production database. The database is fairly large in size as its around 260 GB. The database transaction log file grows around 2.5gb every day. Over the weekend the DBA team noticed that the Log file for this database bloated up to around 230 GB and then seems to hold steady. While troubleshooting I noted an error that the rebuild Index failed due to “Availability_Replica”. Here is the error which we saw in ERRORLOG

SQL SERVER – JSON Support for Transmitting Data for SQL Server 2016 – Notes from the Field #114

February 11, 2016

Pinal Dave

SQL Tips and Tricks

Notes from the Field, SQL Function, SQL Scripts, SQL Server

[Note from Pinal]: In this episode of the Notes from the Field series database expert Kathi Kellenberger explains about JSON Support for Transmitting Data for SQL Server 2016. Kathi is an amazing instructor, she was the SQL author I have read in my early career. The reason, I love SQL Server because her writing has instigated love for this technology in me. Today she brings a relatively interesting topic for database experts. Read the experience of SQL SERVER – JSON from Kathi in her own words.

SQL SERVER 2016: Creating Simple Temporal Table

February 10, 2016

Pinal Dave

SQL Tips and Tricks

SQL Scripts, SQL Server, SQL Server 2016, SQL Utility, Temporal Table

Temporal tables are a new feature that was introduced in SQL Server 2016. A temporal table gives application developers to view the state of data at a point in time. Temporal tables can also be used for logging purposes if required. I wanted to explore how this feature can be used. The documentation has been interesting and I went ahead in trying out how this can be enabled.

One of the most used use case for this feature would be to find the data values in a past date. This can now be easily configured in SQL Server 2016. Let us go ahead and create a database for use and then create a table with the Temporal history database created by default / automatically.

SQL Server Auditing and Recovery With ApexSQL Log 2016

February 9, 2016

Pinal Dave

SQL

ApexSQL, SQL Scripts, SQL Server, SQL Utility

ApexSQL Log is a powerful SQL Server transaction reader for forensic auditing and rollback of malicious and/or unintended changes for Microsoft SQL Server. It is an ideal cost solution for recovery, row changes and/or before-after auditing. ApexSQL Log uses technology which enables it to read online transaction log files or transaction log backup files in order to create auditing results including before and after views of the data as well as the full row history of all changes.

From the recovery standpoint, ApexSQL Log provides sophisticated undo/redo capabilities which enable it to create TSQL scripts which can be used to completely reverse or replay all or only selected transactions read from the online transaction log file and added transaction log backups.

SQL SERVER – How to Connect Using NT AUTHORITY \ SYSTEM Account?

February 8, 2016

Pinal Dave

SQL Tips and Tricks

Command Line, SQL Server, SQL Server Security

Sometimes it is needed to connect to SQL Server using System account. Don’t literally ask me if this is a valid scenario in first place. Someone just pinged to say – they want to do it. I was personally not sure why, but they had their own internal requirement to do the same. Let us learn about in this blog post about how to connect using NT AUTHORITY \ SYSTEM Account?

It is not possible to provide windows credential in SSMS and they are always grayed out. My exploration is always to keep trying to find a solution to such typical use cases. I was able to find that PSExec can be used to achieve this. I am a big fan of some of the tools from sysinternals. These are handy and quite small footprint of the servers. One of the tools I have day-in day-out is ZoomIt while doing presentations.

Interview Question of the Week #057 – What is GO Statement in SQL SERVER?

February 7, 2016

Pinal Dave

SQL Interview Questions and Answers

SQL Scripts, SQL Server

GO is not a Transact-SQL statement; it is often used in T-SQL code. Go causes all statements from the beginning of the script or the last GO statement (whichever is closer) to be compiled into one execution plan and sent to the server independent of any other batches. SQL Server utilities interpret GO as a signal that they should send the current batch of Transact-SQL statements to an instance of SQL Server. The current batch of statements is composed of all statements entered since the last GO, or since the start of the ad hoc session or script if this is the first GO.

MySQL – How to Generate Random Number

February 6, 2016

Pinal Dave

SQL Tips and Tricks

MySQL, SQL Random

In MySQL, UUID() function returns Universal Unique Identifier that generates 36 characters long value which is 5 part hexadecimal numbers. If you want to generate random password, you can make use of this function which generate random number.

Returns the string 85aeb064-8f73-11e5-85ef-02fcc4101968 (Note that this is random, when you execute you will get different value). As the total length is 36, you can make use of the result to get a random password with any length.

SQL SERVER – Install Error – The /UIMode setting cannot be used in conjunction with /Q or /QS

February 5, 2016

Pinal Dave

SQL Tips and Tricks

SQL Error Messages, SQL Server

Doing repetitive tasks is something everyone hates. I am sure many of us have resorted to ingenious techniques to figure out doing the task efficiently. There is no standard tool or technique that everyone uses. Recently I was asked to install a SQL instance with same configuration on 10 servers. Who would like to log in to all those servers, run setup.exe and go through the same setup wizard? Luckily, the SQL Server setup allows to create a configuration file. The very thought of extracting it as configuration is something that made me jump out of my seat. Let us learn about Install Error – The /UIMode setting cannot be used in conjunction with /Q or /QS.

SQL SERVER – SSIS – Get Started with the For Loop Container – Notes from the Field #113

February 4, 2016

Pinal Dave

SQL Tips and Tricks

Notes from the Field, SQL Server, SSIS

[Notes from Pinal]: SSIS is very well explored subject, however, there are so many interesting elements when we read, we learn something new. A similar concept has been Get Started with the For Loop Container.

Linchpin People are database coaches and wellness experts for a data driven world. In this 113th episode of the Notes from the Fields series database expert Tim Mitchell (partner at Linchpin People) shares very interesting conversation related to how to get started with the FOR LOOP Container.

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SQL SERVER InMemory OLTP: Understanding Optimistic Multi-Version Concurrency Concepts

February 3, 2016

Pinal Dave

SQL Performance

In-Memory OLTP, SQL Scripts, SQL Server

InMemory is an awesome concept and I have been fortunate to learn about the same from my friends in the industry over blogs. It holds deep concepts and is sometimes tough to understand how the building blocks come together. I am not the only one doing the exploration, but a number of you also do and pass those learnings to me via your interesting questions. Thanks to each one of you who take a moment to ask me some of these questions that shake the fundamentals and make my understanding stronger. In the same lines, one of the readers wrote back to me after reading the MSDN on InMemory OLTP, what does the concepts of Optimistic multi-version concurrency really mean. On first thought, it looks simple, but the question was very loaded.